What is an IR (infra red ) camera

Cameras with built in infrared are for seeing in total darkness.

If you think of infrared like a torch beam but invisible to the human eye, that will give you an idea of how infrared works. So, if you have a pitch black area with absolutely no lighting an infrared beam will enable the camera to "see", but it will only see what is within the beam (just like if you were in a field at night in pitch black conditions with a torch, you would only see within the torch beam).

So often external lighting and non infrared (but low light capable) cameras will offer better image quality and enable you to see a wider area than a camera with infrared but this also means more hardware and a bit more initial expense in a lot of scenarios.

At ACS ALARMS & CCTV offer both options and a free site survey.